Red light therapy can make the treated area measure a little smaller, according to a few small studies. It is not weight loss, and it works best as one part of a plan.
What does red light do to a fat cell?
One main idea is that the light opens tiny pores in a fat cell for a short time. Some of the fat stored inside leaks out through them, according to a review published in Lasers in Surgery and Medicine in 2013. That same review called the way it works unclear.
In a 2002 study in Plastic and Reconstructive Surgery, a team shone a low level laser on fat removed during surgery from 12 women. Under a microscope, they saw pores open and the fat move out of the cells.
Lab tests from a 2011 trial in Obesity Surgery suggested the fat left the cells without the cells breaking apart.
A team at UT Southwestern Medical Center in Dallas tested the same idea for a 2004 study in Plastic and Reconstructive Surgery. They saw no consistent change in the fat cells.
What do the published studies show?
Trials of a few dozen people found a modest change on the tape measure over two to four weeks. A study that measured the fat itself found no clear drop.
In a 2009 trial in Lasers in Surgery and Medicine, 67 people got a laser or a matching fake treatment for two weeks. By the end, the laser group lost more around the waist, hips and thighs than the fake group did. Two weeks later, they measured a little bigger again.
For the 2011 trial in Obesity Surgery, researchers treated 40 people’s waists, half with a laser and half with a switched off version. A grant from the laser’s maker paid for the trial.
After four weeks, the laser group’s waists measured a little smaller. Over the same weeks, the other group’s waists grew a little. That gap counted as a clear result only in the 31 people whose weight barely changed.
A team in Poland used ultrasound to measure the fat layer itself, for a 2017 study in Lasers in Medical Science. They treated one side of each belly and left the other side alone to compare. Their university paid for the study.
Of 24 people who signed up, 17 had scans before and after. Across those 17, the team could not show a clear drop in fat on the treated side.
A review in Lasers in Medical Science from December 2025 found only three trials that split people at random and measured with a tape. Those three had 160 people between them. Pooled together, the treated groups lost more around the waist than the comparison groups.
Its authors said mixed settings and follow up times make long term results hard to judge.
Every study named here tested a different device from our pads. So none of their results predicts what your own sessions will do.
Will red light therapy change the number on the scale?
Do not expect it to. In the 2011 trial, average weight did not change in any clear way over the four weeks.
At our studio, Contour Light works on a specific area, alongside whatever you are already doing.
Why do we pair red light with cold?
Cold and light do different jobs. Our cold applicator works on one area at a time and breaks down fat cells in that spot. Your body then clears them out over the next few weeks.
Red light treats a larger area at once, such as a whole midsection, both thighs or a full back. It is also gentle: it feels like mild warmth. Some of our clients book it to skip the cold work.
Tracy Eller wrote: “I love the red light therapy on my whole body it feels so good and I feel like I’m losing inches.”
Most of our plans pair it with the cold treatments, because it works best as one part of a plan. The review from 2013 also found too few studies of light alone.
For the cold side of a plan, see our page on fat freezing with CryoSculpting.
Coming to our Creve Coeur studio
You will find us on Old Olive Street Road in Creve Coeur, just off Olive at I-270, with parking right outside.
There is no downtime, so people come in on a lunch break and go back to work. We are open Monday to Thursday from 8:00 AM to 6:00 PM, and Friday from 8:00 AM to 4:00 PM.
What to do next
Measure the area you want to change with a tape, then bring that number to an intro visit. It takes about half an hour, and we will tell you whether light belongs in your plan.
Our page on red light therapy in St. Louis covers what a session feels like and how it fits with the cold treatments.
Call (314) 301-9012, or book an intro visit. If light is the wrong tool for your goal, we will say so.